Is there any benefit?

I recently started New Rules of Lifting for Women and the author says that HIIT is better than long periods of slower or lower-intensity cardio. As in, it's better (for your heart and your cals burned) to run as fast as you can for 60 seconds, then walk at a moderate pace for another 60, then start running again, etc. for half an hour than to jog at a slow pace for half an hour.

slow and long intensity workouts burn stored fat as fuel, while high intensity short workouts burn stored carbohydrate as fuel. BUT while your body is recovering you will burn more calories from fat post workout with high intensity, so its better for weight loss, and usually helps you tone up as well. (I'm a nutrition student so I know this is definitely accurate, and not just something I've read on the internet!)

I attend at HIIT class and love it. I learn something new each time. My body has no idea from day to day what it is in for. Which I believe keeps it from being routine and doesn't allow my body to simply adjust to the change because it is always changing, make sense? The class I attend has a 20-30 minute warm up and then a 20-30 minute class depending on the days "torture" as I call it. Depending on how hard I push myself and if I know the exercise we're doing I can burn anywhere from 550-700 calories within that hour. I read some where that participating in a HIIT style class allows you to continue burning calories up to 4 hours after the class, not sure where I read that but wish I could find it again. There was one day where it took me 48 minutes to get my heart rate back down to the 80's...that day I burned 698 calories. I've yet to wear my HRM for 4 hours after a class to see if I notice a difference from the days we do not have class, but I plan to to. I think too that throwing your body into HIIT is a way to jump start everything. I did and sometimes still do Jillian Michaels 30-Day-Shred and she says something to the effect of, "why are we working big muscles with little muscles, because we want your body to change in as little amount of time as possible. You want big results, they're not coming for free." I really believe that. So when I attend HIIT I know I'm working ALL my muscles, big & little, and when we do 10,9,8,7,6,5,4,3,2,1 reps of everything, by the time I get to 5 or 4 my body is screaming at me. When I go to do just 4 more pull ups my arms are like jelly and they don't want to do more 10,9,8,7,6,5 was enough! By the time I reach 1, I've done a total of 55 pull ups, 55 wall balls, 55 squats...yeah I'm sore haha. But it feels good and it really does burn some serious calories. I'm not sure if what I'm saying helps you or not but I think HIIT rocks. When I can walk away completely spent I feel like I really did something and I can just picture my body changing. It makes me smile - even if I felt like puking.

According to the cutthefatpodcast, the best type of exercise for FAT loss is interval training.